The long-term goals of this program of research are to contribute to the increasing amount of evidence for continued development of the brain into early adulthood. Electroencephalographic (EEC) measures and neuropsychological assessments are being employed to investigate the interrelationships of maturation of specific brain regions and the development of cognitive and emotional processes in children and adolescents. The results obtained from this study will be applied to the development of a model that will elucidate interrelationships of variables representing stimulus-response mechanisms, trait, and state characteristics of an individual and their associated changes in various ERP measurements observed during periodic assessments in typically developing children using a longitudinal design. The goals of the proposed research are to: 1) Determine if developmental trends exist in the reliability of ERPs, and 2) Clarify the relationship of executive functions, specifically attention, to ERPs components and ERP reliability. The research design entails obtaining multiple channel EEC recordings from 30 participants in each of 3 age groups (8-yr olds, 12-yr olds and young adults) while performing 3 ERP paradigms: the novelty auditory oddball (an auditory discrimination task), contingent negative variation (a sustained attention task), and the error-related negativity (error-monitoring in simple visual discrimination task). Each participant will complete these EEG/ERP tasks in each of two visits separated by a 1-2 week period. Split-half and test-retest reliability coefficients will then be determined for the principle components of these ERP paradigms. Split-half and test-retest will then be recomputed using the standardized residuals instead of the original ERP measures. These new reliability coefficients are expected to be higher than those not accounting for variance due to waveform processing. Relationships of attentional measures and ERP reliability and the ERP components (i.e, CNV, P3a, P3b and ERN) will be evaluated. Health related impacts include understanding changes in the brain in relation to attention in childhood and adolescence. In addition, results have the potential of providing a wealth of information regarding individual differences in cognitive ERPs and ERP reliability. This information will be helpful, especially when clinical populations (e.g., attention deficit disorders and learning disabilities) are included in developmental ERP studies. [unreadable] [unreadable]